PB2211: DIFFERENCES IN POST-POLYCYTHEMIA VERA AND POST–ESSENTIAL THROMBOCYTHEMIA MYELOFIBROSIS VS PRIMARY MYELOFIBROSIS IN FIBROTIC STAGE: A RETROSPECTIVE, REAL-WORLD STUDY CONDUCTED IN CHINA
Authors: Shengjie Wang, Lan Zhang, Keyi Jin, Shiwei Hu, Xinlu Zhang, Danhong Xiang, Qiutian Feng, Lingrong Tu, Jie Jin, Jian Huang
Journal: HemaSphere (2023)

Topic: 16. Myeloproliferative neoplasms - Clinical Background: There was less information on post-PV/ET MF, and most studies have focused on PMF, post-PV/ET MF was considered to be similar to PMF. However, with increasing research in recent years, people found that post-PV/ET MF may differ from PMF. Aims: To explore the differences in clinical characteristics, molecular genetics and prognosis among overt-PMF, post-PV MF and post-ET MF. Methods: A total of 338 MF patients in the first affiliated hospital and the fourth affiliated hospital of Zhejiang University school of medicine from October 2013 to November 2022 (ChiCTR2200061208). Results: Among the 338 MF patients, 40 were post-PV MF, 62 were post-ET MF and 236 were over PMF, including 186 males and 152 females, with a median age of 65 (29-89). In terms of clinical characteristics, compared with post-PV MF, overt PMF patients had a lower incidence of thrombotic events and were more likely transfusion dependence; post-PV MF patients had higher the level of WBC and HGB than those with post-ET MF or overt PMF; the PLT level of post-ET MF patients at diagnosis was higher than that of over PMF patients. 25.1% (85/338) of MF patients present abnormal karyotypes, including 6 were post-PV MF, 14 were post-ET MF, and 65 were over PMF. The common abnormal karyotypes in overt PMF include +8, -20/20q-, -13/13q-, chromosome 1 translocation/duplication, -11/11q-, +9, etc; the common abnormal karyotypes in post-ET MF include chromosome 1 translocation/ duplication, +8, etc; the common karyotypes in post-PV MF include -17, -5/5q-, etc. Interestingly, single chromosome 1 translocation/duplication has a higher incidence in triple-negative post-ET MF. In the terms of gene mutations, the most common non-driving gene mutations were ASXL1 and TET2 in MF patients, while the distribution of other mutations was different slightly. Splicing body and RNA metabolism gene mutations are more common in overt PMF, including SRSF2, ZRSR2, SF3B1, U2AF1, etc. The survival analysis showed that patients with post-PV MF have better survival than those with overt PMF and post-ET MF. Summary/Conclusion This study reflects the characteristics of MF patients in China and confirms the differences in clinical characteristics, cytogenetics, molecular biology and prognosis among overt PMF, post-ET MF and post-PV MF. More clinical studies with a longer follow-up are needed to confirm the disease-associated features in patients with overt PMF, post-ET MF and post-PV MF. This research was funded by the Key R&D Program of Zhejiang, No. 2022C03137; Public Technology Application Research Program of Zhejiang, China, No. LGF21H080003; Zhejiang Medical Association Clinical Medical Research special fund project, No. 2022ZYC-D09; the Key Project of Jinhua Science and Technology Plan, China, No. 2020-3-011. *Correspondence to: Prof Jian HuangKeywords: Differentiation, Myelofibrosis